Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner
1 - 17 of 17 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter · #1 ·
Hi everyone, I would like to ask if anyone had experienced a loud knock sound when the tranny is shifting from 1st to 2nd gear? I'm at 120k miles and this abnormality just started. The tranny fluid level is fine the color is brown, no leaks the previous owner never serviced the transmission it had 76k when I became the owner. This knock is quite loud and I can actually feel it in the steering wheel. There's no other issues with 1st,3nd or 4th gear or when coming to full stop it only happens the second it goes from 1st to 2nd.. I took it to a tranny repair shop in my area and they told me to drive it until the transmission dies and then either rebuild or replace the transmission they think it's something internal since no faulty codes are present. I noticed they weren't too interested to find the issue. Any ideas? Thank you in advance! 2004 Envoy SLT 4WD
 

·
Premium Member
2002 Chevrolet TrailBlazer LTZ 4.2L
Joined
·
195 Posts
Sounds like you need a second opinion from a better shop. Also sounds like if you don't get this sorted out sooner than later, you'll be left stranded somewhere waiting for a tow.
 
  • Like
Reactions: Alexi

·
Registered
Joined
·
7 Posts
Discussion Starter · #3 ·
Sounds like you need a second opinion from a better shop. Also sounds like if you don't get this sorted out sooner than later, you'll be left stranded somewhere waiting for a tow.
Thank you! I will definitely find another shop for a second opinion. That’s exactly what I’m afraid of being stranded far from home.
 

·
Premium Member
2002 Chevrolet TrailBlazer LTZ 4.2L
Joined
·
195 Posts
When it comes to expensive rebuilds like this, a shop with a wait and see attitude is your mortal enemy. It could be something as small as a broken mount, bad u-joint or even a damaged axle. A relatively easy and somewhat inexpensive fix now becomes a major undertaking. I wish you the best.
 
  • Like
Reactions: Alexi

·
Premium Member
'05 Chevy TB EXT
Joined
·
4,394 Posts
In the THM700R4 to the THM4L70 series transmission, if the 2/4 servo has a broken spring, it will eventually seize in the bore, ruining the case and the results of destroying the case too means the case is damaged and cannot be repaired.

What you're describing is just that situation.

When something starts to act up --- THEN is the time to fix it --- not after it takes out a lot more expensive parts and might metal-out the transmission heat exchanger and pump and - well --- it just gets more and more expensive.

Somebody's lying to you. Go somewhere else and get a real opinion.

That said ---> from long distance and on the interwebs - get it rebuilt NOW instead of next week. It's crying to you now.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #6 ·
In the THM700R4 to the THM4L70 series transmission, if the 2/4 servo has a broken spring, it will eventually seize in the bore, ruining the case and the results of destroying the case too means the case is damaged and cannot be repaired.

What you're describing is just that situation.

When something starts to act up --- THEN is the time to fix it --- not after it takes out a lot more expensive parts and might metal-out the transmission heat exchanger and pump and - well --- it just gets more and more expensive.

Somebody's lying to you. Go somewhere else and get a real opinion.

That said ---> from long distance and on the interwebs - get it rebuilt NOW instead of next week. It's crying to you now.
Thank you! I got in touch with another shop they will take a look Friday. I’ll come back with an update.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #7 ·
When it comes to expensive rebuilds like this, a shop with a wait and see attitude is your mortal enemy. It could be something as small as a broken mount, bad u-joint or even a damaged axle. A relatively easy and somewhat inexpensive fix now becomes a major undertaking. I wish you the best.
Thank you! Agreed, I’ll will visit another shop on Friday, hopefully they’ll be more helpful.
 

·
Premium Member
'05 Chevy TB EXT
Joined
·
4,394 Posts
I hope it becomes something simple like a loose bellhousing or sumpthin' like that.
 

·
Premium Member
'05 Chevy TB EXT
Joined
·
4,394 Posts
Don't forget to have them check the flexplate for cracks. Good luck!
Uhmmmmm ... I dont think so.

The OP said:

"This knock is quite loud and I can actually feel it in the steering wheel. There's no other issues with 1st, 3nd or 4th gear or when coming to full stop it only happens the second it goes from 1st to 2nd...... "
..... and it surely would be noisy making the other shifts too.

Good thought though.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #11 ·
Hi everyone, I would like to ask if anyone had experienced a loud knock sound when the tranny is shifting from 1st to 2nd gear? I'm at 120k miles and this abnormality just started. The tranny fluid level is fine the color is brown, no leaks the previous owner never serviced the transmission it had 76k when I became the owner. This knock is quite loud and I can actually feel it in the steering wheel. There's no other issues with 1st,3nd or 4th gear or when coming to full stop it only happens the second it goes from 1st to 2nd.. I took it to a tranny repair shop in my area and they told me to drive it until the transmission dies and then either rebuild or replace the transmission they think it's something internal since no faulty codes are present. I noticed they weren't too interested to find the issue. Any ideas? Thank you in advance! 2004 Envoy SLT 4WD
Hi guys, today June 16 the tranny finally died! I was driving and suddenly heard a sound similar to a manual transmission when the clutch is not fully engaged and you shift gears ( metal to metal grinding sound ) I stopped and called AAA they towed it to a tranny shop near by that later today quoted me $1400 for a rebuild. I'm still thinking about it not sure what to but if I decide to rebuild it I'll get back with an update. Thank you all the for the previous answers and suggestions.
 

·
Premium Member
'05 Chevy TB EXT
Joined
·
4,394 Posts
That price sounds like a repair, not a rebuild ... or the old AAxxx Bait & Switch ... or a junkyard used transmission.

You ALREADY have a used transmission --- why would you want another one?

Beware!

Be VERY aware!
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #14 ·
$1400 bucks for a rebuild on a 4L60 4WD is pretty cheap. What are they going to replace?
Hi, I went to the shop yesterday to ask about more details and they’re going to replace a lot of parts including bands, clutches and more parts that look like gears of different sizes. I saw all parts laying on the table but now the price increased to $1700. But I’m still very happy with the price it could higher. Hopefully it’s going to be ready for testing today.
 

·
Premium Member
'05 Chevy TB EXT
Joined
·
4,394 Posts
Bands --- of which you only have one --- are legally part of an overhaul, so charging extra for that is probably illegal.
~ Clutches too, since they are friction material(s) are also part of an overhaul and charging extra for them is illegal.
~ Showing you - an uninformed customer - "parts on the table" - is a ploy by unscrupulous "transmission repair" shops, aimed at intimidation to a customer.

Doing this has been illegal in the two states where I did business - and is usually a ploy of prevarication by the worst offender in this instance --- a place with a big "A" in the front of it's name.

That one shop has been ordered by the California BBB and the state's AG to "cease and desist from advertising" for years at a time.

But I just KNOW you took my advice and didn't go to any place like that --- right?

Still-n-all ---- $1700.00 is pretty close to free and I wonder if they are going to take your transmission to the local junior high and let them overhaul it for you - as a learning experience.

I hear that The Campfire Girls offer a merit badge in Transmission Overhaul now.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #16 ·
$1400 bucks for a rebuild on a 4L60 4WD is pretty cheap. What are they going to replace?
Hi, I went to the shop yesterday to ask about more details and they’re going to replace a lot of parts including bands, clutches and more parts that look like gears of different sizes. I saw all parts laying on the table but now the quote increased to $1700. But I’m still very happy with the price it could higher. Hopefully it’s going to be ready for testing today.
Bands --- of which you only have one --- are legally part of an overhaul, so charging extra for that is probably illegal.
~ Clutches too, since they are friction material(s) are also part of an overhaul and charging extra for them is illegal.
~ Showing you - an uninformed customer - "parts on the table" - is a ploy by unscrupulous "transmission repair" shops, aimed at intimidation to a customer.

Doing this has been illegal in the two states where I did business - and is usually a ploy of prevarication by the worst offender in this instance --- a place with a big "A" in the front of it's name.

That one shop has been ordered by the California BBB and the state's AG to "cease and desist from advertising" for years at a time.

But I just KNOW you took my advice and didn't go to any place like that --- right?

Still-n-all ---- $1700.00 is pretty close to free and I wonder if they are going to take your transmission to the local junior high and let them overhaul it for you - as a learning experience.

I hear that The Campfire Girls offer a merit badge in Transmission Overhaul now.
I appreciate the invaluable information you provided! Since I don’t know much about transmissions. It was my first time seeing so many parts.

This shop in particular has good reputation and it was recommended to me by a friend who had his tranny rebuild 8 years ago and to this day he has 0 issues. I will also get a receipt that explains in detail every part involved which I’m going to share this forum. I’m also getting a 1 year warranty for this job.
 
1 - 17 of 17 Posts
Top